L14 Kin Selection 2

Question 1

Frequency dependent selection

Answer 1

Less offspring => more fitness

More offspring => less fitness

even sex ratio => males and females have equal average fitness

Question 2

The two castes

Answer 2

1. Queens

2. Workers

Question 3

Darwin on social insects

Answer 3

Is kin selection the answer?

Question 4

Ants, bees and wasps are haplodiploid

Answer 4

Males are haploid

Females are diploid

Question 5

Full sisters and super sisters

Answer 5

r = 0.75

Question 6

Males are always half brothers to their siblings

Answer 6

r = 0.25

Question 7

Workers reproduction

Answer 7

• workers are unmated in most species but can produce sons asexually
• related to their own kids by 0.5

Question 8

But! Haplodiploids also have lower sister-brother relatedness

Answer 8

also, eusociality arose in several diploid taxa and there are some non-eusocial haplodiploids too

maybe haplodiploidy is a red herring

Question 9

Why was this rather obvious theory (monogamy) ignored until the 2000s?

Answer 9

Honey bees are not monogamous

However, the ancestors of all eusocial insects were probably monogamous

Question 10

Cooperative breeding

Answer 10

Cooperative breeding

- Evolve from relatively monogamous ancestors 
- Worth helping your parents to rear siblings if they are your full siblings and not half siblings

Question 11

So, what about haplodiploidy?

Answer 11

• seems monogamy is more important

- the fact that eusociality evolved so many times in haploidiploids mean something?

Question 12

Virgin haploidiploids can and do reproduce

Answer 12

Haplodiploid

• Females can have kids without a mate
• Can only produce sons
• Some of the nests are full of boys
• Other nets have a mixture of males and females since the queen has successfully mated

Question 13

Virgin reproduction selects for “split sex ratios”

Answer 13

So the earliest workers might have mostly reared full sisters (r=0.75) which are more valuable than their own offspring (r=0.5)

Question 14

Relatedness-dependent matricide in wasps

Answer 14

Matricide

• Whether or not the mother is killed is correlated to how often the mother has remated
• Wasps can tell how many times the mother has mated
• If she’s singly mated, they kill her

Question 15

Relatedness-dependent matricide in wasps

Answer 15

Matricide

• Whether or not the mother is killed is correlated to how often the mother has remated
• Wasps can tell how many times the mother has mated
• If she’s singly mated, they kill her

Question 16

Worker policing

Answer 16

• if worker most related to the sons of the queen, workers don’t really reproduce in this case
• if workers most related to the sons of other works, workers reproduce more in this case

Question 17

Worker policing

Answer 17

• if worker most related to the sons of the queen, workers don’t really reproduce in this case
• if workers most related to the sons of other works, workers reproduce more in this case
• when policing is effective, workers don’t bother trying to lay eggs

Question 18

Dominant meerkats kill subordinates’ offspring and evict the transgressor

Answer 18

Subordinates to try to breed, kill the offspring and kick out that meerkat

Question 19

Adult phenotype is determined by juvenile environment, which individuals have little control over

Answer 19

Whether you develop into a queen bee or worker bee

• Queen bees grow up in a queen cell
• Workers have little option but to cooperate

Question 20

The monogamy hypothesis

Answer 20

Monogamy - genetic monogamy

- The whole colony has the genes from one mum and one dad 
- Just as related to your own kids than you are to your siblings 
- If rearing siblings than having your own kids, then you become a sterile helper 
- The VERY first bee is well adapted to be a solidary organism, doesn't have social behaviours just yet so B is unlikely to be a lot higher than C

Question 21

eusociality

Answer 21

Eusocial animals share the following four characteristics: adults live in groups, cooperative care of juveniles (individuals care for brood that is not their own), reproductive division of labor (not all individuals get to reproduce), and overlap of generations (Wilson 1971).